Grinding/polishing systems and methods having proximity sensors

ABSTRACT

An example grinder/polisher system includes: a specimen holder configured to secure a specimen; a platen; an actuator configured to move at least one of the specimen holder and the platen; a sensor configured to detect objects within a field of view of the sensor; and a controller configured to control movement of the actuator and to stop the actuator in response to detection of an object by the sensor while the actuator is moving.

RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 63/105,725, filed Oct. 26, 2020, entitled “GRINDING/POLISHING SYSTEMS AND METHODS HAVING PROXIMITY SENSORS.” The entirety of U.S. Patent Application Ser. No. 63/105,725 is expressly incorporated herein by reference.

BACKGROUND

This disclosure relates generally to grinding/polishing systems and, more particularly, to grinding/polishing systems and methods having proximity sensors.

Grinding and polishing operations are performed on specimens for numerous purposes and across a vast array of sectors and industries. In some applications, surface preparation of a specimen by grinding/polishing operations is a prerequisite to specimen testing, such as microscopic examination, which is relied on to test materials and components, for example, in the manufacturing sector. Grinding/polishing devices are capable of performing both grinding operations and polishing operations to work a specimen to a required finish for a particular application.

SUMMARY

Grinding/polishing systems and methods having proximity sensors are disclosed, substantially as illustrated by and described in connection with at least one of the figures, as set forth more completely in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example grinding/polishing device having one or more sensing devices configured to detect entry of a foreign object to a volume proximate the grinding/polishing device, in accordance with aspects of this disclosure.

FIG. 2 is a block diagram representative of the example grinding/polishing device of FIG. 1.

FIGS. 3A and 3B are plan view of the example grinding/polishing device of FIG. 1, including example sensing devices and corresponding fields of view for detecting foreign objects.

FIG. 4 is a flowchart representative of an example machine readable instructions which may be executed by the controller of FIG. 2 to turn off one or more actuators of a grinding/polishing device in response to detecting entry of a foreign object into a volume.

The figures are not necessarily to scale. Wherever appropriate, similar or identical reference numerals are used to refer to similar or identical components.

DETAILED DESCRIPTION

Grinding/polishing systems involve grinding and/or polishing a specimen using one or more motors or other actuators. The polished specimen may then be used to test a manufacturing or other process that resulted in the specimen, such as by performing visual inspection, hardness testing, and/or any other desired testing. However, physical interference with the grinding/polishing operation, such as by contact between a foreign object and the grinding/polishing equipment and/or the specimen, is undesirable.

Disclosed example grinding/polishing systems and methods monitor a volume around the grinding/polishing operation and/or equipment, and automatically shut off or disable the equipment (e.g., motors, actuators, etc.) in response to detecting a foreign object in proximity to the grinding/polishing operation. Example techniques that may be used to monitor the volume include ultrasonic sensing, retroreflective proximity sensing, optical and/or image sensing, and/or use of a light curtain. The example grinding/polishing systems prevent further use or operation of the grinding/polishing systems until detection of removal of the foreign object.

For the purpose of promoting an understanding of the principles of the claimed technology and presenting its currently understood, best mode of operation, reference will be now made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the claimed technology is thereby intended, with such alterations and further modifications in the illustrated device and such further applications of the principles of the claimed technology as illustrated therein being contemplated as would typically occur to one skilled in the art to which the claimed technology relates.

As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” The embodiments described herein are not limiting, but rather are exemplary only. It should be understood that the described embodiments are not necessarily to be construed as preferred or advantageous over other embodiments. Moreover, the term “embodiments” does not require that all disclosed embodiments include the discussed feature, advantage, or mode of operation.

As utilized herein the terms “circuits” and “circuitry” refer to physical electronic components (i.e. hardware) and any software and/or firmware (“code”) which may configure the hardware, be executed by the hardware, and or otherwise be associated with the hardware. As used herein, for example, a particular processor and memory may comprise a first “circuit” when executing a first set of one or more lines of code and may comprise a second “circuit” when executing a second set of one or more lines of code. As utilized herein, “and/or” means any one or more of the items in the list joined by “and/or”. As an example, “x and/or y” means any element of the three-element set {(x), (y), (x, y)}. In other words, “x and/or y” means “one or both of x and y”. As another example, “x, y, and/or z” means any element of the seven-element set {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}. In other words, “x, y and/or z” means “one or more of x, y and z”. As utilized herein, the term “exemplary” means serving as a non-limiting example, instance, or illustration. As utilized herein, the terms “e.g.” and “for example” set off lists of one or more non-limiting examples, instances, or illustrations. As utilized herein, circuitry is “operable” to perform a function whenever the circuitry comprises the necessary hardware and code (if any is necessary) to perform the function, regardless of whether performance of the function is disabled or not enabled (e.g., by an operator-configurable setting, factory trim, etc.).

Disclosed example grinder/polisher systems include a specimen holder configured to secure a specimen, a platen, an actuator configured to move at least one of the specimen holder and the platen, a sensor configured to detect objects within a field of view of the sensor, and a controller configured to control movement of the actuator and to stop the actuator in response to detection of an object by the sensor while the actuator is moving.

In some example grinder/polisher systems, the controller is configured to identify a background signal from the sensor in response to initiation of an operation involving movement by the actuator, and detect an object based on comparing a monitoring signal from the sensor to the background signal. In some examples, the controller is configured to detect the object when a difference between the monitoring signal and the background signal satisfies a threshold.

In some example grinder/polisher systems, the actuator includes a motor and a driver actuator, and the controller is configured to control (i) the motor to rotate at least one of the specimen holder and the platen in accordance with selected grinding/polishing parameters, and (ii) the drive actuator to press the specimen or the platen into the other of the specimen and the platen in accordance with a selected load applied. Some example grinder/polisher systems further include a user interface, in which the controller is configured to output a notification via the user interface in response to the detection of the object.

In some examples, the sensor includes at least one of an ultrasonic sensor, a retroreflective proximity sensor, an optical sensor, or a light curtain sensor. Some example grinder/polisher systems further include a plurality of sensors including the sensor, in which the plurality of sensors are configured to monitor a corresponding plurality of sub-volumes proximate the platen. In some examples, the controller is configured to disable the actuator until detection, via the sensor, of removal of the object.

Disclosed example methods to control a grinder/polisher involve: controlling, via a controller, an actuator to move at least one of a specimen holder and of a grinder/polisher system or a platen of the grinder/polisher system; and, in response to detecting, via a sensor, an object within a field of view of the sensor while the actuator is moving, controlling the actuator to stop.

Some example methods further involve: identifying a background signal from the sensor in response to initiation of an operation involving movement by the actuator; and detecting an object based on comparing a monitoring signal from the sensor to the background signal. In some example methods, wherein detecting the object occurs when a difference between the monitoring signal and the background signal satisfies a threshold.

In some example methods, controlling the actuator involves controlling (i) a motor of the actuator to rotate at least one of the specimen holder and the platen in accordance with selected grinding/polishing parameters, and (ii) a drive actuator of the actuator to press the specimen or the platen into the other of the specimen and the platen in accordance with a selected load applied. Some example methods further involve outputting a notification via a user interface in response to the detection of the object.

In some example methods, detecting the object via the sensor involves detecting the object via at least one of an ultrasonic sensor, a retroreflective proximity sensor, an optical sensor, or a light curtain sensor. In some example methods, detecting the object via the sensor comprises detecting the object via at least one of a plurality of sensors configured to monitor a corresponding plurality of sub-volumes proximate the platen. Some example methods further involve disabling the actuator until detection, via the sensor, of removal of the object.

FIG. 1 illustrates an example grinding/polishing system 100 having one or more proximity devices and configured to detect entry of a foreign object to a volume proximate the grinding/polishing system 100. The grinding/polishing system 100 includes a power head assembly 102 with a specimen holder 112 with specimens 116 (one shown), a cabinet or base 104 with a bowl 106, and an input device or unit control panel 122.

The bowl 106 forms an opening in the base 104. The bowl 106 includes a removable bowl liner (not shown), such as a transparent plastic bowl liner, to prevent accumulation of debris, contaminant, and residue in the bowl. A splash guard 109 may further be positioned around the bowl 106 to contain the fluid in the bowl and minimize over-spray, and to prevent items from unintendedly entering the bowl or contacting a moving component of the grinding polishing device, such as the platen 108 or specimen holder 112.

The platen 108 is installed in the bowl 106. A pad 110 is secured to the top of the platen 108 and is configured to contact the specimens 116 during a grinding/polishing cycle. Many types of pads 110 may be used in a grinding/polishing operation. For example, the pad 110 may be a grinding disc, such as a silicon carbide grinding disc or a diamond grinding disc. In other embodiments, the pad 110 may be a polishing pad. The platen 108 is operably connected to an actuator, as described in more detail below with reference to FIG. 2. As an example, the underside of the platen 108 may include openings for receiving drive pins on the top of a drive plate of an actuator to secure the platen 108 to the actuator, but many other mechanisms may be used to secure the platen to the actuator.

The platen 108 (e.g., via an actuator controlled by the controller) is controlled to rotate, oscillate, or otherwise move to work the specimen 116 during a grinding/polishing operation.

The power head assembly 102 is secured to the base 104 and positions the specimen holder 112 with respect to the platen 108. In the embodiment depicted, the specimen holder 112 includes a number of specimen receiving slots 114 that hold specimens 116 (one shown) subject to a grinding/polishing operation by the system 100. The specimen holder 112 is operably connected to an actuator of the power head assembly 102. In the embodiment shown, the specimen holder 112 is removably secured to an actuator 118 via a chuck 115.

Fluid dispenser 120 is located on the base 104 and positioned to dispense water and, in embodiments as the one depicted, may dispense other types of fluid onto the platen 108. Fluid dispensed onto the platen 108 may be collected in the bowl 106, and drained as needed. The dispenser includes valves that may be operated to control the dispensation flow rate.

Fluids that may be dispensed may include, for example, water, suspensions including diamond and other suspensions, polishing suspensions, lubricants and other fluids. In certain embodiments, one or more fluids may be supplied by one or more dispensers. In embodiment where multiple fluids are dispensed, such as water and another type of fluid, the water and the other fluid(s) are provided by respective supply lines (not shown), such as water service lines and fluid supply lines. In embodiments, water and other fluids are supplied from a reservoir or canister tank located on the device or located remotely. The controller may also provide automatic control of the fluid which may be selected by the user at the control panel. In embodiments, controller 190 operates the dispenser to turn the dispenser on and off and to adjust the flow rates.

While in the illustrate example, the dispenser 120 may dispense water from one nozzle and another type of fluid from a second nozzle shown, in other examples, the second nozzle may be part of a second dispenser that is a standalone unit and separate from the base 104. In such embodiments, the fluid flow from may be controlled by the standalone unit, for example, manually by a knob or by a controller of the standalone dispenser unit. The second nozzle may be positionable next to the system 100 and, in embodiments, secured to the base 104.

The unit control panel 122 displays, among other things, grinding/polishing device data and information, and receives input from a user. In embodiments, the unit control panel may include various buttons, knobs, switches, sliders, displays, touch screens, touch pads, lights, indicia, and so on, to display information and receive input from a user. The unit control panel 122 may further include other components, such as peripheral device, audio circuits and speakers, microphones, communications devices (wired or wireless), and other components as will be recognized. In the example of FIG. 1, unit control panel 122 has a touch-sensitive display 124. As illustrated in FIG. 1, a manual control knob 121 is also positioned on the base 104 and operable to control the volume of flow rate delivered by the dispensers 120.

To reduce or prevent interference with a grinding/polishing operation during movement of the platen 108, the example grinding/polishing system 100 includes one or more sensors 152, which are positioned and configured to detect objects (e.g., hands, tools, etc.) within a field of detection of the corresponding sensor(s) 152. In the example of FIG. 1, sensors 152 are configured to detect objects that enter a volume 154 proximate the grinding/polishing system 100 and, more particularly, proximate the moving components of the system 100 (e.g., the platen 108, the pad 110, etc.). While the example volume 154 is depicted as a cylinder, the volume 154 may be any shape or size based on the desired volume to be monitored for foreign objects.

Example sensors that may be used to implement the sensors 152 to detect foreign objects include ultrasonic sensors, retroreflective proximity sensors, optical sensors (e.g., cameras), light curtain sensors, and/or any other sensors. As discussed in more detail below, during a grinding or polishing operation, if one or more of the sensors 152 detects the presence of a foreign object, the platen 108 and/or other moving objects are shut down and the unit control panel 122 may output a visual and/or audible notification of the detection.

FIG. 2 is a block diagram representative of the example grinding/polishing system 100 of FIG. 1. As illustrated in FIG. 2, the grinding/polishing system 100 includes a controller 190, which is connected to a machine readable storage device 191, actuators 117, 118, the control panel 122, and the sensors 152.

The control circuitry or controller 190 comprises circuitry (e.g., a microcontroller and memory such as a non-transitory machine readable storage device 191) operable to process data from the actuators 117, 118, the dispenser 120, and the unit control panel 122. For example, the controller 190 may include processor(s) and/or other logic circuitry that controls the operations of the grinding/polishing device. Example processor(s) may include one or more microprocessors, such as one or more “general-purpose” microprocessors, one or more special-purpose microprocessors and/or ASICS, one or more microcontrollers, and/or any other type of processing and/or logic device. For example, the controller 190 may include one or more digital signal processors (DSPs). The controller 190 is operable to receive user input signals from the unit control panel 122 and, in response, control components of the grinding/polishing device such as the actuators, dispensers, components thereof, and other elements of the device.

The actuator 117 rotates, oscillates, and/or otherwise moves the platen 108 to work the specimen 116 during a grinding/polishing operation. In some examples, the actuator 117 is a bi-directional motor configured to rotate the platen 108 at selected speeds and in either direction. In other examples, the actuator 117 includes a motor operable to oscillate or otherwise move the platen 108 so as to work the specimen 116.

In some examples, the actuator 118 is configured to move the platen 108 towards and/or away from the specimen 116 in order to adjust the load or force applied between the platen and specimen (e.g., a linear-type actuator controlled to move or drive the platen towards and away from the specimen). Many types of actuators may be used to facilitate a grinding/polishing operation.

The actuator 118 is controlled to rotate, oscillate, or otherwise move the specimen holder 112 (and specimen 116) with respect to the platen 108 (and pad 110) to work the specimen 116 during a grinding/polishing operation. The actuator 118 in the illustrated example includes a bi-directional motor configured to rotate the specimen holder 112 at selected speeds and in either direction, and further includes a linear-type actuator configured to press the specimen holder 112 (with specimen 116) towards or away from the platen 108 in order to adjust the load or force applied between the specimen and platen. In some examples, the actuator is configured to oscillate or move the specimen holder 112 with respect to the platen during an operation. Any desired actuator may be used.

The controller 190 operates the dispenser 120 to turn the dispenser 120 on and off and to adjust the flow rates. The controller 190 further controls the actuators 117, 118 to configure and/or perform grinding and/or polishing operations.

As discussed above, detection of foreign objects by the sensors 152 causes stopping of a grinding or polishing operation. To this end, the example controller 190 monitors signals from the sensors 152 to detect whether the sensors 152 have detected a foreign object (e.g., within the volume 154). In response to detecting an object by the sensors 152 while one or both of the actuators 117, 118 are moving, the controller 190 stops the actuators 117, 118 to mitigate the effects of possible impending contact between the foreign object and the grinding/polishing system 100. In some examples, the controller 190 programmatically prevents further movement by the actuators 117, 118 while the foreign object is detected (e.g., until the foreign object is removed).

In some examples, to detect a foreign object, the sensors 152 (e.g., an ultrasonic sensor, a retroreflective proximity sensor) are used to measure a baseline or background measurement at the start of a grinding/polishing procedure, in which no foreign objects are expected to be present (e.g., both hands of the operator are required to be outside of the volume 154 to start the operation, such as by pushing multiple buttons to start the operation). For example, ultrasonic sensors may measure a baseline distance measurement from the sensor to the platen 108, in which the volume 154 to be monitored is positioned between the ultrasonic sensors and the platen 108. As a result, any foreign object entering the volume 154 would result in a smaller distance measurement than the baseline measurement, and controller 190 may detect the foreign object(s) by comparing measurements taken during the grinding or polishing operation with the baseline or background measurement. For example, if the change in the distance measurement is more than a threshold (e.g., a noise filtration threshold), the controller 190 detects that a foreign object is present.

In some other examples, one or more of the sensors 152 are cameras or other optical sensors, which provide images to the controller 190. The controller 190 may use image recognition techniques to detect the entry of a foreign object into the field of view of the camera or optical sensor. In some examples, the controller 190 may be trained to ignore the spinning motion of the platen 108, the pad 110, the specimen holder 112, and/or any other objects that could interfere with foreign object detection. Additionally or alternatively, the controller 190 may apply filters to filter or otherwise ignore the components of the grinding/polishing system 100. If the controller 190 determines that a difference between a baseline or default image and a monitored image satisfies a difference threshold, the controller 190 may detect that a foreign object is present.

FIG. 3A is a plan view of the example grinding/polishing system 100 of FIG. 1, including an example arrangement of sensors 302 a, 302 b, 302 c, 302 d and corresponding fields of view 304 a, 304 b, 304 c, 304 d for detecting foreign objects. In the example of FIG. 3A, the sensors 302 a, 302 b, 302 c, 302 d are arranged on the power head assembly 102 over the platen 108, such that the fields of view 304 a-304 d are directed down toward the platen 108 and outwards from the power head assembly 102.

FIG. 3B is a plan view of the example grinding/polishing system 100 of FIG. 1, including another example arrangement of sensors 312 a, 312 b, 312 c, 312 d and corresponding fields of view 314 a, 314 b, 314 c, 314 d for detecting foreign objects. In the example of FIG. 3B, the sensors 312 a, 312 b, 312 c, 312 d are located on the base 104, such that the fields of view 304 a-304 d are directed upwards from the base 104 toward the power head assembly 102.

The fields of view 304 a-304 d, 314 a-314 d may be implemented as sub-volumes of the volume 154 to be monitored, and the respective sensors 302 a-302 d, 312 a-312 d detect foreign objects within the respective sub-volumes to, as a whole, detect foreign objects within the monitored volume 154.

While example arrangements are disclosed with reference to FIGS. 3A and 3B, other numbers of one or more sensors, arrangements of the sensors, and/or other configurations may be used based on the volume 154 to be monitored and/or the structure of the grinding/polishing system 100. In some examples, the fields of view of the sensors overlap to provide redundancy between sensors, such that multiple sensors are required to detect a foreign object to take action.

FIG. 4 is a flowchart representative of an example machine readable instructions 400 which may be executed by the controller of FIG. 2 to control one or more actuators of a grinding/polishing device based on detecting entry of a foreign object into a volume. The example instructions 400 are described below with reference to the example grinding/polishing system 100 of FIGS. 1 and 2.

At block 402, an operator and/or the controller 190 configures a grinding/polishing operation. For example, the operator may provide a specimen and/or configure parameters of the grinding/polishing operation via the unit control panel 122.

At block 404, the controller 190 determines whether a grinding/polishing operation has started. For example, the controller 190 may determine whether the operator has started the grinding/polishing operation via inputs. Example inputs involve both of the operator's hands, such as multiple buttons spaced apart on the base 104, to avoid the presence of the operator's hands in the volume 154 when the operation begins. If a grinding/polishing operation has not started (block 404), control returns to block 402 to continue configuring the operation.

In response to the start of the grinding/polishing operation (block 404), at block 406 the controller 190 obtains baseline measurement(s) from one or more sensor(s) 152 monitoring the volume 154 (and/or portions of the volume 154). The example sensor(s) 152 may include ultrasonic sensors, retroreflective proximity sensors, optical sensors (e.g., cameras), light curtain sensors, and/or any other sensors capable of detecting objects in the field of view of the sensor. In examples involving cameras or other image-based sensors and image processing for identifying foreign objects,

At block 408, the controller 190 controls the actuator(s) 117, 118 to perform the grinding/polishing operation. The controller 190 may control the actuator(s) 117, 118 according to the configured parameters.

At block 410, the controller 190 obtains monitoring measurement(s) from the sensor(s) 152. For example, the controller 190 may obtain one or more measurement(s) from each of the same sensor(s) 152 as the baseline measurements in block 406. In examples involving cameras or other image sensors, the example controller 190 may obtain image(s) from each of the image sensor(s).

At block 412, the controller 190 determines whether monitoring measurement(s) indicate the presence of a foreign object in the monitored volume (e.g., the volume 154, the fields of view 304 a-304 d, 314 a-314 d). For example, the controller 190 may compare each monitoring measurement(s) to the respective baseline measurement obtained from the same respective sensor(s) 152. In an example involving ultrasonic sensors, a distance measurement from an ultrasonic sensor during the grinding/polishing operation may be compared to a baseline distance measurement. If the difference satisfies a threshold (e.g., the change in distance is more than a threshold change), the controller 190 may determine that a foreign object is present. In some other examples in which an image sensor is used, the controller 190 may perform one or more image processing techniques on the image(s) obtained during the grinding/polishing operation.

If the monitoring measurement(s) do not indicate the presence of a foreign object (block 412), at block 414 the controller 190 determines whether the grinding/polishing operation has ended. If the grinding/polishing operation has not ended (block 414), control returns to block 408 to continue controlling the actuator(s) 117, 118. If the grinding/polishing operation has ended (block 414), control returns to block 402 to configure a next grinding/polishing operation.

If the monitoring measurement(s) indicate the presence of a foreign object (block 412), at block 416 the controller 190 turns off the actuators 117, 118 (e.g., to stop movement of the platen 108, specimen holder 112, and/or other components). In some examples, the controller 190 may activate a brake to more quickly slow down movement of the platen 108, the specimen holder 112, and/or other components. Additionally or alternatively, the controller 190 may control the actuators 117, 118 to apply force in an opposing direction to quickly reduce movement speed of the platen 108, specimen holder 112, and/or other components. At block 418 the controller 190 obtains additional monitoring measurement(s) from the sensor(s) 152. Block 418 may be performed in a similar or identical manner as block 410.

At block 420, the controller 190 determines whether the operator has attempted to resume the grinding/polishing operation. Resuming of the grinding/polishing operation may be similar or identical to starting of the grinding/polishing operation in block 404, but may resume the grinding/polishing operation instead of restarting the grinding/polishing operation from the beginning. If the grinding/polishing operation is to be resumed (block 420), at block 422 the controller 190 determines whether the monitoring measurements indicate the removal of the foreign object from the monitored volume. For example, block 422 may be performed in a similar manner as block 412 by determining whether a foreign object is present based on the monitoring measurement(s).

If the foreign object has not been removed (block 422), control returns to 416 to maintain the actuators 117, 118 in an off state (e.g., disabled). If the foreign object has been removed (block 422), control returns to block 408 to resume the grinding/polishing operation and control the actuators 117, 118 to perform the grinding/polishing operation.

If the grinding/polishing operation is not to be resumed (block 420), at block 424 the controller 190 determines whether the grinding/polishing operation has ended. If the grinding/polishing operation has ended (block 424), control returns to block 402 to configure a next grinding/polishing operation. If the grinding/polishing operation has not ended (block 424), control returns to 416 to maintain the actuators 117, 118 in an off state (e.g., disabled).

Methods and systems described may be realized in hardware, software, or a combination of hardware and software. The methods and/or systems may be realized in a centralized fashion in at least one computing system or in a distributed fashion where different elements are spread across several interconnected computing systems. Any kind of computing system or other apparatus adapted for carrying out the methods described herein is suited. A typical combination of hardware and software may include a general-purpose computing system with a program or other code that, when being loaded and executed, controls the computing system such that it carries out the methods described herein. Another typical implementation may comprise an application specific integrated circuit or chip. Some implementations may comprise a non-transitory machine-readable (e.g., computer readable) medium (e.g., FLASH drive, optical disk, magnetic storage disk, or the like) having stored thereon one or more lines of code executable by a machine, thereby causing the machine to perform processes as described herein.

The foregoing description and accompanying figures illustrate the principles, preferred embodiments, and modes of operation. However, the disclosure should not be construed as being limited to the particular embodiments discussed above. Additional variations of the embodiments discussed above will be appreciated by those skilled in the art.

While the present method and/or system has been described with reference to certain implementations, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the present method and/or system. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from its scope. For example, block and/or components of disclosed examples may be combined, divided, re-arranged, and/or otherwise modified. Therefore, the present method and/or system are not limited to the particular implementations disclosed. Instead, the present method and/or system will include all implementations falling within the scope of the appended claims, both literally and under the doctrine of equivalents. While the controllers and methods are described as being employed in connection with a grinding/polishing device, the teachings may be similarly applied to other devices where it is desirous to determine control grinding and/or polishing operations.

All documents cited herein, including journal articles or abstracts, published or corresponding U.S. or foreign patent applications, issued or foreign patents, or any other documents are each entirely incorporated by reference herein, including all data, tables, figures, and text presented in the cited documents. 

What is claimed is:
 1. A grinder/polisher system, comprising: a specimen holder configured to secure a specimen; a platen; an actuator configured to move at least one of the specimen holder and the platen; a sensor configured to detect objects within a field of view of the sensor; and a controller configured to control movement of the actuator and to stop the actuator in response to detection of an object by the sensor while the actuator is moving.
 2. The grinder/polisher system of claim 1, wherein the controller is configured to: identify a background signal from the sensor in response to initiation of an operation involving movement by the actuator; and detect an object based on comparing a monitoring signal from the sensor to the background signal.
 3. The grinder/polisher system of claim 2, wherein the controller is configured to detect the object when a difference between the monitoring signal and the background signal satisfies a threshold.
 4. The grinder/polisher system of claim 1, wherein the actuator comprises a motor and a driver actuator, the controller further configured to control (i) the motor to rotate at least one of the specimen holder and the platen in accordance with selected grinding/polishing parameters, and (ii) the drive actuator to press the specimen or the platen into the other of the specimen and the platen in accordance with a selected load applied.
 5. The grinder/polisher system of claim 4, further comprising a user interface, the controller configured to output a notification via the user interface in response to the detection of the object.
 6. The grinder/polisher system of claim 1, wherein the sensor comprises at least one of an ultrasonic sensor, a retroreflective proximity sensor, an optical sensor, or a light curtain sensor.
 7. The grinder/polisher system of claim 1, further comprising a plurality of sensors including the sensor, the plurality of sensors configured to monitor a corresponding plurality of sub-volumes proximate the platen.
 8. The grinder/polisher system of claim 1, wherein the controller is configured to disable the actuator until detection, via the sensor, of removal of the object.
 9. A method to control a grinder/polisher system, the method comprising: controlling, via a controller, an actuator to move at least one of a specimen holder and of a grinder/polisher system or a platen of the grinder/polisher system; and in response to detecting, via a sensor, an object within a field of view of the sensor while the actuator is moving, controlling the actuator to stop.
 10. The method of claim 9, further comprising: identifying a background signal from the sensor in response to initiation of an operation involving movement by the actuator; and detecting an object based on comparing a monitoring signal from the sensor to the background signal.
 11. The method of claim 10, wherein detecting the object occurs when a difference between the monitoring signal and the background signal satisfies a threshold.
 12. The method of claim 9, wherein controlling the actuator comprises controlling (i) a motor of the actuator to rotate at least one of the specimen holder and the platen in accordance with selected grinding/polishing parameters, and (ii) a drive actuator of the actuator to press the specimen or the platen into the other of the specimen and the platen in accordance with a selected load applied.
 13. The method of claim 12, further comprising outputting a notification via a user interface in response to the detection of the object.
 14. The method of claim 9, wherein detecting the object via the sensor comprises detecting the object via at least one of an ultrasonic sensor, a retroreflective proximity sensor, an optical sensor, or a light curtain sensor.
 15. The method of claim 9, wherein detecting the object via the sensor comprises detecting the object via at least one of a plurality of sensors configured to monitor a corresponding plurality of sub-volumes proximate the platen.
 16. The method of claim 9, further comprising disabling the actuator until detection, via the sensor, of removal of the object. 